| 摘要 |
PURPOSE:To improve the adhesion of a solder resist to a printed wiring board by providing a two-layered structure consisting of hard and soft layers to a photosensitive layer and by adhering the soft layer to the uneven surface of the wiring board. CONSTITUTION:Hard and soft photosensitive layers are successively laminated on a light transmsitting film 1 of polyethylene terephthalate or the like. The hard photosensitive layer is a layer 2 of a solid photosetting resin composition such as a photosetting acrylate resin composition. The soft photosensitive layer is a layer 3 of a photosetting resin composition which is solid at ordinary temp. and liq. under heating such as an acrylate resin composition. The soft photosensitive layer may be coated with a protective film 4. When the soft photosensitive layer 3 is adhered to the uneven surface of a printed wiring board in a liq. state, it is well adhered because air is removed. The photosensitive layers 2, 4 are then irradiated with light through a prescribed pattern to set the resins. Thus, the adhesion of the resulting solder resist can be improved by forming the soft photosensitive layer. |
